Analysis of Structural Strength and Deformation Properties of Intact Loess
SONG Zhang1,CHENG Qian-gong1,ZHANG Wei 2 ,MENG Fan-chao3
1 .Southwest Jiaotong University,Chengdu,Sichuan 610031,China;2. Institute of Geotechnical Investigation& Design,MMI,Xi' an,Shanxi 710043,China;3.China Highway Planning and Design Institute,Beijing 100010, China
Abstract:Research purposes: Based on the testing,this paper analyzes the microstructure properties of intact loess and the internal logic of the characteristics of strength and deformation with microstructure of intact loess.
Research methods: Adopted the scanning electron microscopy ( SEM)of microstructure and static triaxial shear tests of intact loess,this paper analyzes the microstructure feature and the characteristics of strength and deformation of Q3,Q2 intact loess.
Research results: With the increasing of embedding depth,the microstructure feature of intact loess changed gradually from the bracketed-macropore weak-cemented texture to the inlaid-micropore half-cemented texture,the void properties changed from bracketed-macropore void to void among grains,then to micropore void. The microstructure feature of loess was one of important factors which dominated the characteristics of the strength and deformation of loess, upper Q3 loess layers,with greater stabilizability of microstructure than changeability,the curves types of stress-strain of loess in the process of loading appeared as the softening obviously deformation properties. With the increasing of embedding depth and confining pressures,the stabilizability of the microstructure of lower Q2 loess layers was less than its changeability,and the curves types of stress-strain of loess in the process of loading put up the hardening observably deformation properties.
Research conclusions: The characteristics of the strength and deformation of intact loess were the comprehensive effect of the stabilizability and changeability of microstructure of loess,which correlated closely to the characteristics of linked and tactic of loess grains.